Windows, Android: building //examples/android/java/bazel:hello_world is broken at HEAD

[laszlocsomor]

$ git rev-parse HEAD
9ebc4b222c5eb3d788ec4f6ae837d8e745105b02

I built Bazel, then used the binary to build the Android example:

C:\work\bazel>C:/tmp1/o6hbs7n0/execroot/io_bazel/bazel-out/msvc_x64-fastbuild/bin/src/bazel.exe build //examples/android/java/bazel:hello_world --python_path=c:\Python27\python.exe
(...)
ERROR: C:/tempdir/temp/_bazel_laszlocsomor/o6hbs7n0/external/androidsdk/com.android.support/BUILD:419:1: AarResourcesExtractor external/androidsdk/com.android.support/_aar/unzipped/resources/appcompat-v7-25.0.0 failed (Exit 1).
Traceback (most recent call last):
  File "c:\tempdir\temp\Bazel.runfiles_ek1fej\runfiles\io_bazel\..\bazel_tools\tools\android\aar_resources_extractor.py", line 68, in <module>
    main()
  File "c:\tempdir\temp\Bazel.runfiles_ek1fej\runfiles\io_bazel\..\bazel_tools\tools\android\aar_resources_extractor.py", line 64, in main
    ExtractResources(aar, FLAGS.output_res_dir)
  File "c:\tempdir\temp\Bazel.runfiles_ek1fej\runfiles\io_bazel\..\bazel_tools\tools\android\aar_resources_extractor.py", line 53, in ExtractResources
    aar.extract(name, output_res_dir)
  File "c:\Python27\lib\zipfile.py", line 1028, in extract
    return self._extract_member(member, path, pwd)
  File "c:\Python27\lib\zipfile.py", line 1079, in _extract_member
    os.mkdir(targetpath)
WindowsError: [Error 206] The filename or extension is too long: u'bazel-out\\android-arm-linux-androideabi-clang3.8-v7a-gnu-libstdcpp-fastbuild\\bin\\external\\androidsdk\\com.android.support\\_aar\\unzipped\\resources\\appcompat-v7-25.0.0\\res\\drawable-xxhdpi-v4'

/cc @aj-michael

[aj-michael]

I'm not aware of any Android changes that would have extended this path length

[laszlocsomor]

The reason seems to be that aar_resources_extractor uses MAX_PATH (260) as the length limit before creating junctions, which is fine for files, but for directories the limit is 248. I'll fix that.

Also, aar_embedded_jars_extractor also needs to handle long paths, so I'll fix that too to use junctions.